Fog suppressing gas burning heater system



FOG SUPPRESSING GAS BURNING HEATER SYSTEM 2 Sheets-Sheet 1 Filed NOV. 5,1945 @ff/lla@ @ams gym Ms Aug. 1, 1950 F. A. RYDER ErAL Eos sUPPREssINGGAS BURNING HEATER SYSTEM 2 Sheets-Sheet 2 Filed Nov. 5, 1945 PatentedAug. 1, 1950.

UNITED STATES PATENT OFFICE FOG SUPPRESSING GAS BURNING HEATER SYSTEMApplication November 5, 1945, Serial No. 626,604

This invention relates generally to heating systems, and moreparticularly to improved heating systems for small buildings.

It is customary to provide a chimney or stack for carrying away theproducts of combustion of a furnace or other heater, even in the case ofheating systems particularly adapted for use in small buildings. Achimney represents a considerable proportion of the cost of a building.The proportionate cost of a chimney in a small building is especiallyhigh, and the elimination of the need for a chimney in such buildingsresults in a great saving in construction costs. The heating system ofthe invention provides for the discharge of the products of combustioninto the exterior atmosphere through the side wall of the building, thusmaking it unnecessary to provide a chimney, and yet providing for thepositive flow of such products from the heater. With such anarrangement, there is objectionable condensation of moisture containedin the combustion products upon contact with the relatively cold outerair. This is particularly true of gas fired heaters. To prevent thepossibility of such condensation, meansare provided in the present`heating system so that condensation does not occur upon such contact.

It is an object of this invention to provide an improved heating system,particularly adaptable for heating small buildings, which eliminates theneed for a chimney.

Another object is to provide an improved heating system particularlyadaptable for small buildings in which means areprovided for dischargingproducts of combustion through a side wall of the building.

A further object is to provide an improved heating system, particularlyadaptable for small buildings, discharging the products of combustionthrough a side wall of the building, in which means are provided toprevent the formation of a cloud of condensed vapor at the exhaustoutlet. i

It is also an object of the invention to provide a heating systemdischarging products of combustion through a side wall of a building tothe exterior thereof and having means for diffusing the products ofcombustion through an air stream for discharge in mixed conditiontherewith. v

Other objects and advantages of the present invention will becomeapparent from the ensuing description of an embodiment thereof, in thecourse of which reference is had to the accom-- panying drawings, inwhich:

2 Claims. (Cl. 158-7) Fig. 1 is a central vertical sectional viewthrough the heater, with parts in elevation and parts in fragmentarysection;

Fig. 2 is a horizontal cross sectional view taken substantially alongthe line 2 2 of Fig. 1, with parts in elevation and parts in fragmentarysection; and

Fig. 3 is a fragmentary elevational view taken substantially along theline 3--3 of Fig. 2, with parts in fragmentary section.

This invention is in the nature of an improvement on the heating systemdisclosed in the copending application Serial No. 596,130, filed May 28,1945, by Theodore Y. Korsgren and Frank A. Ryder and now abandoned.

The heater is illustrated as comprising a substantially cylindricalhousing Ii! suitably secured at its upper edge to a flange il. Theflange is shown as circular in shape and is secured to the flooring Itby screws not shown. A register l2 covers the opening in the floor andis supported by a horizontal ange portion lll. The register has aplurality of sloping baies IB, the spaces between the central balilesproviding ports for the discharge of heated air as indicated by theupwardly directed arrows in Fig. 1, while the spaces between the outerbales provide ports for the admission of Ventilating air, as indicatedby the downwardly directed arrows. Since the upward flow of heated airis at a substantial velocity, the heated air will be forced into theroom while cool air will iiow along the floor and downwardly between theouter bailles.

Filters 2i! may be provided to remove foreign matter from, thedownwardly moving air. Each lter may comprise a pair of spacedforaminated plates 22 between which a suitable filtering material 24 isdisposed. The iilters 2li may be supported between an upper aperturedrectangular plate 26 and a lower apertured partition plate 23 to causethe entering air to flow through the filters in the directions indicatedby the arrows.

The heating unit comprises a casing 3B of generally cylindrical shapehaving an adapter 32 at the top thereof providing a generallyrectangular outlet. A flaring pipe section 3ft of rectangular crosssection is secured to the adapter 32 and is provided with deflectors 36at its upper end. The casing 3!) has its lower end joined to an inletextension 38 which has legs lil resting upon the bottom wall 42 of thehousing` Iii. A heat exchanger 44 is suitably mounted in the casing 3U.The heat exchanger is shown as being of the spiral type wherein theproducts of combustion ow `spirally outwardly from a center chamber 3 46through a spiral passageway 48 to an exhaust or outlet tting 50, thisfitting extending through the housing l0.

Combustion takes place within a combustion chamber 52 secured to theheat exchanger M and communicating directly with the center chamber 4tthereof. l In the particular heater shown, domestic gas is used as thefuel and is supplied through a pipe 513. Gas is supplied to a pilotburner 55, projecting into the combustion chamber, through a conduit 58.Gas for normal combustion is supplied to a main burner nozzle 63 througha conduit S2. The flow through thereonduits 58 and 62 is controlled bysuitable valve mechanisms @il and tt, respectively, which may be of thesolenoid-actuated type well known in the art. A spark plug 68 having itselectrode within the combustion chamber 52 may be employed to effectignition of the pilot flame.

Circulation of Ventilating air through the heater is induced by a fan'IB driven by a motor l2 suitably supported from the legs iii). The fandraws cool air downwardly through the :housing I3 about .the casing 33and blows it upwardly through the spiral passageway formed by the wallsofthe exl'iaust passageway 48 `and the casing 30, as indicated by thearrows in Fig. 1.

A thermostat (not shown) may be employed to control the operation of themain burner te and fan 'it to maintain a vdesired temperature in theroom or building being heated. A manual control rod M may be providedfor starting and stopping the operation of the heater as desired, thiscontrol rod controlling energization ci the spark plug 65 and flow ofgas through the pilot flame control valve mechanism til. As shown in 1,the rod it may actuate both a lever l5 for controlling electric switchesin a box i8, and a lever I9 for opening and closing a pushbettom typevalve 82 in the valve mechanism 54.

An exhaust pipe et is connected 'by a suitable adapter fitting 83 to theoutlet tting tti, and, as shown in Fig. 2, extends substantialiyhorizontally to a side wall 84 of the building. A `discharge conduit S6jackets the exhaust pipe Bil, having one end closed and secured to theexhaust pipe an adapter '38 adjacent the heater. rEhe other end of thedischarge conduit t@ projects beyond the discharge end of the exhaustpipe tt, and extends `through the wall so as to vent to the exterioratmosphere. The exhaust pipe 89 and discharge conduit Sii may be held insuitably spaced relation by spacing means (not shown) of any suitabletype. By this arrangement, no chimney or vertical flue is required inthe building, 'since the exhaust gases are led through a relativelyshort conduit from the heater to the open air. The fiow of exhaust gasesis not hindered by the absence of ra vertical passage therefor', Vsothat the efficiency of the heating system is not lowered. At the sametime, `the construction cost of the building is reduced, and the troubleand expense incident to the cleaning and maintenance of a chimney isavoided. The construction just described, therefor, by which the exhaustgases kare discharged horizontally through a side wall instead ofvertically through the roof, is distinctly advantageous.

lidiffuser '99 is connected to the discharge end of the exhaust pipe St,and may suitably take the form of a perforated cap, although itmay be ofany other desired construction as, for example, an open tubular memberwith perforations in the wall thereof. A baille plate 92 is secured inthe conduit 86 between the Vopen end thereof and the diffuser 90 tocause turbulence and thereby promote better mixing.

An air inlet conduit 9d has one end thereof extending through the wall84, with the other end connected to a flaring adapter fitting 96 whichleads to the housing S8 of a blower -I driven by motor 62. The lattermay -be supported from the housing ill by a suitable bracket l |34. Asuitable adapter IDS connects the blower housing 98 with two conduitsHi8 and Ht, a portion of the air drawn through the inlet conduit 94being forced through each of these conduits |03 and I lil by the blowerThe conduit ISB leads to the combustion chamber 52 to conduct air forcombustion to the burner. The products of com bustion pass from theburner into the center chamber fit and through the spiral exhaustpassageway lit, outlet fitting 5t, and adapter fitting e3 into theexhaust pipe 8G;

The conduit lill leads from the blower to the discharge conduit 843,being connected thereto in any suitable manner adjacent the `closed endthereof, as by means of a branch 8l of the conduit S6. A portion of theair drawn through the inlet conduit 94 thus by-passes the heater vandflows through the discharge conduiti and around the exhaust pipe Se tovent to the atmosphere. In its passage through the discharge'conduit 85,this air, which may conveniently be termed diluent air, niingles withthe products of combustion `issuing from the exhaust pipe through thediffuser de, the mixing of the exhaust gases and diluent air beingpromoted by the restriction provided `by the baiile plate 92. Themixture flows past the baffle plate 92 to the atmosphere. The portionsof the discharge conduit 86 and the inlet conduit 94 which projectthrough the wall 813 may conveniently be disposed adjacent-each other,sothat a single opening in the wall may accommodate both conduits. Ascreen or iilter l t3 maybe provided in the inlet conduit 96 to bar theingress of foreign bodies. A suitable shield `or hood (not shown) may beprovided to shield the open ends of the conduits 865 and 9d from rainandthe like.

The exhaust gases or products of combustion produced in the burner andpassing through the exhaust pipe contain a high proportion Aof moisture.The exhaust gases are at an elevated temperature, and this elevatedtemperature com,- bined with the high moisture content results in thegases having a relatively high dew point. If the exhaust gases aredischarged directly into the relatively cold outside air, normallyApresent during the operation of a heating system, an objectionablecloud of condensed vapor might-form immediately adjacent the outlet andthe wall l84 of the building unless the exhaust gases are very hot. Inthe apparatus described, the addition of diluent air at the diffuser 90and the provision of baille plate 92 prevent such cloud formation. Thediluent air and exhaust gas mixture has a temperature somewhat lowerthan that of the exhaust gases, but still considerably higher than theoutside atmosphere. The mixture also 'has a somewhat lower proportion ofmoisture than the exhaust gases, since the diluent air does not contain'as large a proportion of moisture as do the exhaust gases. The relativehumidity of the mixture of diluent air and exhaust gases is thereforelower, resulting in a lower dew point for the mixture. When this mixtureof lower dew point passes into the outer atmosphere, none or very littlevapor condenses, and no vapor cloud is formed.

The cloud preventing effect depends upon the temperature of the exhaustgases and the quantity and humidity of diluent air. The higher theexhaust gas temperature, and the greater the quantity of air mixedtherewith within limits, the better the results obtained. This generalstatement of the principle involved is subject to limitations imposed bypractical considerations, but most satisfactory results are obtainedWithin these limitations by applying the two factors mentioned, that is,the high exhaust gas temperature and the quantity of diluent air, invarying combinations. Increasing the exhaust gas temperature andincreasing the quantity of di1- uent air both tend to decrease theover-all efficiency of the heating system, and it is therefore desirablenot to increase the exhaust gas temperature or the diluent air flow ratemore than necessary to prevent the clouding eifect.

As an example, we have found that with an exhaust gas having atemperature of between 500 degrees and 600 degrees Fahrenheit theaddition of about 20 to 30 per cent diluent air is sufcient, if theexhaust pipe is short. Without any diluent air much higher exhausttemperatures would be necessary.

The maintenance of a high temperature in the exhaust gases is assistedby the flow of diluent air about the exhaust pipe, which results ininsulating the exhaust pipe against substantial heat loss. Most of theheat lost by the exhaust gases is transferred to the diluent air, whichis of advantage since it is not lost to the system inasmuch as thediluent and exhaust air are to be mixed eventually anyway. Therefore,the temperature of the mixed gases at the discharge end of the pipe 30is only slightly less than they would be at the outlet fitting 50. Thediluent air thus serves both to conserve the heat of the exhaust gasesuntil the zone of mixing adjacent the diffuser 90 and baffle plate 92 isreached, and to produce with the exhaust gases a mixture of hightemperature and low relative humidity and consequent loW dew point, asalready explained. In order to get the full benet of this insulatingeffect, especially with long thin exhaust pipes.

more diluent air should be used than proposed above. For instance, witha pipe fifteen feet long, as much as 200 per cent diluent air can beused to advantage.

Instead of jacketing the exhaust pipe by the discharge conduit 86, theexhaust gases and the diluent air may be conveyed separately to a mixingfitting or chamber and discharged therefrom to the outer atmosphere, ifdesired. In this case, the diluent air would not jacket the exhaust pipeand provide heat insulation therefor, and accordingly it would bedesirable to insulate the exhaust pipe against heat loss.

With exhaust pipes which are relatively short, the mixing of diluent airand exhaust gases may take place at a point quite close to the heater.In such case, the jacketing of the short length exhaust pipe 3B by thedischarge conduit 86, or the insulation thereof by other means, would beunnecessary. It appears that the location of the mixing zone relativelyclose to the outlet to the atmosphere is the important consideration. Ifthis location is relatively remote from the heater,

6 provision should be made to minimize the heat loss from the exhaustpipe, while if this location is close to the heater as well as to theoutlet, the heat loss is so slight as to render unnecessary anyinsulation of the exhaust pipe.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. In a heating system including a gas burner, an exhaust pipe toconduct `products of combustion including a high concentration of watervapor from said burner, a fog suppressing system comprising a perforatedextension on the discharge end of said pipe for diffusing said products,a conduit surrounding said pipe for substantially its full length andterminating in the outside atmosphere in a venting end beyond saidextension, means restricting the interior of said conduit intermediatesaid extension and said venting end, and means to force air through saidconduit about said pipe and extension in the direction oi flow of saidcombustion products, the last said means introducing said air into saidconduit adjacent said heater, whereby heat insulation is provided forsaid pipe and said combustion products and air are intermingled in thevicinity of said extension and restricting means to provide a low dewpoint mixture for discharge to the atmosphere.

2. In a heating system including means forming a combustion chamber anda gas burner therein, a pipe connected to said combustion chamber forexhausting combustion products having a high concentration of watervapor therein from the combustion chamber, a conduit surrounding saidpipe for substantially its full length and terminating in the outsideatmosphere to define an annular space between said conduit and saidpipe, means to force cold atmospheric air into said annular spaceadjacent said combustion chamber, and means at the outlet end of saidexhaust `pipe for mixing air from said conduit with the products ofcombustion from said exhaust pipe adjacent the termination ot saidconduit and for exhausting said mixture to the atmosphere.

FRANK A. RYDER. THEODORE Y. KORSGREN. ARTHUR Rf. COLLINS.

REFERENCES CITED The following references are of record :ln the file ofthis patent:

UNITED STATES PATENTS Number Name Date 345,107 Brinkerhoi July 6, 18861,353,740 Gillespie Sept. 2l., 1920 1,604,271 Friedman Oct. 26, 19261,629,921 Mansfield May 24, 1927 1,773,870 Schmidt Aug. 26, 19301,869,939 Latimer Aug. 2, 1932 2,286,855 Holthouse June 16, 19422,385,652 Rifle Sept. 25, 1945 FOREIGN PATENTS Number Country Date234,896 Great Britain June 4, 1925

